IS JOHN FORD'S STORY the story of American movies? Many film critics and historians would answer with a resounding yes. Which makes Scott Eyman's new biography, Print the Legend: The Life and Times of John Ford, one of the most important books ever written on the subject of movies.

Eyman, who has written a highly regarded biography of Ernst Lubtisch and a ground-breaking history of the talkies, The Speed of Sound, has given us a 600-plus-page book without an ounce of fat. John Ford's career began before World War II; he died as the Vietnam War was heating up; and in between, he directed, among scores of other films, The Lost Patrol, The Informer, Stagecoach, The Grapes of Wrath, How Green Was My Valley, My Darling Clementine, Fort Apache, She Wore a Yellow Ribbon, Rio Grande, The Quiet Man, The Searchers and The Man Who Shot Liberty Valance. The careers of John Wayne and Henry Fonda might never have happened if not for these films.

A liar of colossal proportions, John Martin Feeney--he later claimed to have been named Sean Aloysius O'Fearna in order to seem more Irish, as if that were really necessary--was born in Maine in 1895. Entirely self-taught, he broke into films in the silent era. Early on, he began to exhibit the self-conscious lack of style that defined his craft. Ford despised "director's touches" and tried "to make people forget they're in a theater," Eyman writes, and began to display the penchant toward control of his work that is summed up in his phrase "Give me the script and leave me alone."

By 1938, Ford was ready to begin an incredible run of films that became, as Eyman notes, "America's vision of itself, and the world's [vision of America]." The man himself was an S.O.B.," said an actress who worked with him early in his career, "a demonical man." To his son, Pat, he was "a lousy father, but he was a good movie director and a good American."

How mean could John Ford be? During the filming of The Searchers in Monument Valley, Ariz., a scorpion stung him. A few minutes later, John Wayne reported to the producer, "It's O.K. John's fine; it's the scorpion that died."

Wayne had good reason to know. For the better part of three decades Ford alternately brutalized and coddled him, molding him into a superstar in public and deriding him in private for his failure to join the service in World War II. Behind Wayne's back, Ford mocked him. Wayne took it from "the dirty son of a bitch" because, as he admitted later in life, "I wouldn't be here today if it wasn't for him."

If John Ford sounds like a man who inspired contradictory reactions in others, it was a reflection of his inner self. All his life he engaged in vicious anti-gay remarks while in person befriending and sometimes employing gays.

On one occasion, he was approached by an old actor from his silent films who asked to borrow $200 for his wife's operation. Ford, who was incapable of dealing with the emotions inspired by such a request, punched the man, shouted at him and walked away--then rented a limo to take him and his wife to the hospital where he paid the bills for the operation.

Nowhere did the volcanic contradictions of Ford's nature show more vividly than in his politics. Which was the real John Ford, the director of the most beloved populist American film of all time, The Grapes of Wrath, or the man who was alarmed that director John Huston was "seeking refuge in our beloved Ireland" because Huston "is not of the Right Wing"? The man who went out of his way to invite Nazi propagandist filmmaker Leni Riefenstahl to his home, or the man who, during the Hollywood witch hunts, declared, "send the Commie bastard to me. I'll hire him"?

The answer is that both sides and many more were the real Ford. "His true political religion was to be contrary, a one-man insurrection against perceived manners and mores," Eyman writes. "Filmmaking, not alcohol, was Ford's primary narcotic, and nostalgia his primary emotion." For better--and sometimes, it could be argued, for worse--John Ford took a powerful nostalgia for an America and an Ireland that never were and made them our own.

Print the Legend: The Life and Times of John Ford by Scott Eyman; Simon & Schuster; 627 pages; $40 cloth.